44Ti self-diffusion in nanocrystalline thin TiO2 films produced by a low temperature wet chemical process

Abstract

Grain boundary self-diffusion of titanium in nanocrystalline TiO2 films is investigated in an extended temperature interval by the radiotracer technique applying the 44Ti isotope. The diffusion annealing treatments are performed at low and high oxygen partial pressures. At low oxygen partial pressure Ti grain boundary self-diffusion follows an Arrhenius type temperature dependence with the pre-exponential factor of 7.25×10−12m2/s and the activation enthalpy of 74.7kJmol−1. At high oxygen partial pressure Ti diffusion follows an Arrhenius type temperature dependence below 773K and changes drastically the behavior above 773K indicating a possible grain boundary structure transition.